Efficient in-situ catalyst sulfiding methods and systems

ABSTRACT

A system and method is disclosed for efficiently sulfiding metal catalyst resident in a reactor vessel comprises a sulfiding module and a hydrogen sulfide detection module and a remote computer all arranged and configured to communicate wirelessly and to allow remote control and monitoring of the modules and sulfiding process.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims benefit of and priority to U.S. ProvisionalApplication Ser. No. 61/852,396, filed on Mar. 15, 2013, the entirecontents of which are incorporated herein for all purposes.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO APPENDIX

Not applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The inventions disclosed and taught herein relate generally to methodsand apparatuses for sulfiding a hydrocarbon processing catalyst; andmore specifically to methods and apparatuses for sulfiding a hydrocarbonprocessing catalyst resident in a reactor.

2. Description of the Related Art

Hydroprocessing units, such as hydrotreaters, hydrodesulfurizers andhydrocrackers, found in hydrocarbon refineries utilize metal catalyststo aid the chemical reactions. These catalysts require periodicsulfiding to reach maximum catalytic activity. For purposes of thisdisclosure, “sulfiding” means causing the reaction of a catalyst metalwith hydrogen sulfide.

There are several ways to sulfide catalyst already packed in a reactorvessel, commonly referred to as in-situ sulfiding, such as by using thenaturally occurring sulfur in the hydrocarbon feed stock (aka sourfeed). While avoiding the cost of an independent source of sulfur, usingfeedstock sulfur can be time consuming and potentially harmful if thesulfur content is not carefully monitored or high enough. An alternativeto using feedstock sulfur is to use an independent sulfur source such asmercaptans, sulphides, disulphides, polysulphides and sulfoxides, suchas Dimethyl Disulfide (DMDS), Dimethyl Sulfide (DMS), Dimethyl Sulfoxide(DMSO), di-tertiary-butyl polysulfide (TBPS), tertiary nonylpolysulfide(TNPS) and refinery acid gas. These sulfur sources can be used toperform in-situ liquid phase sulfiding or in-situ gas phase sulfiding.

In general, within the hydroprocessing unit, sulfur is reacted withhydrogen to form hydrogen sulfide (H₂S). The metal oxide catalysts arereacted with hydrogen sulfide (H₂S) and hydrogen (H₂) at elevatedtemperatures to form the active metal sulfide, such as MoS₂, CO₉S₈, WS₂or Ni₃S₂, in an exothermic reaction. Theoretically, only thestoichiometric amount of sulfur is needed to activate the catalyst.However, in the real world of commercial refineries, it is common to usemore than the stoichiometric amount of sulfur to ensure completesulfiding. Excess sulfur creates excess hydrogen sulfide and othersulfiding products that must be disposed of or otherwise dealt with.

Liquid DMDS is often used as the sulfur source because of its highsulfur density by weight (compared to the other potential sulfursources) and lack of solid or overly reactive decomposition products,which absence reduces coking. DMDS can be injected into the hydrocarbonfeed stream as a liquid or into the hydrogen recycle loop as a gas.Under temperature and pressure, DMDS will decompose into H₂S at severaltemperature ranges including about 350° F. to about 450° F.; about 390°F. to about 500° F. and about 450° F. to about 520° F.

The inventions disclosed and taught herein are directed to methods andapparatuses for efficiently sulfiding catalysts packed in a reactorvessel.

BRIEF SUMMARY OF THE INVENTION

As a brief summary of one of many possible embodiments of ourinventions, a system for sulfiding a metal catalyst comprises a mobilesulfur supply module comprising a sulfur product inlet and outlet, asulfur product measurement device, a sulfur product pressurizationdevice having a variably controllable output, a controller in electricalcommunication with at least the measurement device and pressurizationdevice, and a first communication device configured to transmitinformation between the module and an external site; a mobile detectionmodule comprising an inlet and outlet, a hydrogen sulfide concentrationdetection device located between the inlet and outlet, a hydrogen gasconcentration detection device located between the inlet and the outlet,and a second communication device configured to transmit informationbetween the hydrogen sulfide detection device and the external site andbetween the hydrogen gas detection device and the external site.

As brief summary of another of many possible embodiments of ourinventions, a system for liquid phase in-situ sulfiding of a metalcatalyst, comprises a sulfur supply module comprising a fluidmeasurement device comprising a Coriolis meter, a fluid pump having avariably controllable output comprising an A/C motor and a variablefrequency drive, a controller in electrical communication with at leastthe measurement device and variable frequency drive, and a firstwireless communication device configured to transmit information to andfrom the module; a mobile detection module comprising a hydrogen sulfideconcentration detection device located between a detection module inletand outlet, a hydrogen gas concentration detection device locatedbetween the inlet and the outlet, and a second communication deviceconfigured to transmit information to and from the hydrogen sulfidedetection device and to and from the hydrogen gas detection device.

As yet another brief summary of another possible embodiment of ourinventions, any of the previously summarized systems may furthercomprise an Internet website configured to receive informationtransmitted by the sulfur supply module, the hydrogen sulfide detectionmodule and the hydrogen gas detection module, and to display theinformation received in substantially real time.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The following figures form part of the present specification and areincluded to further demonstrate certain aspects of the presentinvention. The invention may be better understood by reference to one ormore of these figures in combination with the detailed description ofspecific embodiments presented herein.

FIG. 1 illustrates an exemplary hydroprocessing unit to which thepresent inventions may be implemented.

FIG. 2 illustrates the hydroprocessing unit of FIG. 1 with a sulfidingmodule according to the present invention.

FIG. 3 illustrates one of many possible sulfiding modules according tothe present inventions.

FIG. 4 illustrates the hydroprocessing unit of FIG. 1 with a sulfidingmodule and a detection module according to the present invention.

FIG. 5 illustrates one of many possible detection modules according tothe present inventions.

FIG. 6 illustrates a typical sulfiding temperature profile according tothe present invention.

FIG. 7 illustrates hydrogen sulfide concentration as a function of time,and sulfur product flow rate as a function of time according to thepresent invention.

FIG. 8 illustrates one of many possible graphical user interfaces foruse with the present inventions.

While the inventions disclosed herein are susceptible to variousmodifications and alternative forms, only a few specific embodimentshave been shown by way of example in the drawings and are described indetail below. The figures and detailed descriptions of these specificembodiments are not intended to limit the breadth or scope of theinventive concepts or the appended claims in any manner. Rather, thefigures and detailed written descriptions are provided to illustrate theinventive concepts to a person of ordinary skill in the art and toenable such person to make and use the inventive concepts.

DETAILED DESCRIPTION

The Figures described above and the written description of specificstructures and functions below are not presented to limit the scope ofwhat Applicants have invented or the scope of the appended claims.Rather, the Figures and written description are provided to teach anyperson skilled in the art to make and use the inventions for whichpatent protection is sought. Those skilled in the art will appreciatethat not all features of a commercial embodiment of the inventions aredescribed or shown for the sake of clarity and understanding. Persons ofskill in this art will also appreciate that the development of an actualcommercial embodiment incorporating aspects of the present inventionswill require numerous implementation-specific decisions to achieve thedeveloper's ultimate goal for the commercial embodiment. Suchimplementation-specific decisions may include, and likely are notlimited to, compliance with system-related, business-related,government-related and other constraints, which may vary by specificimplementation, location and from time to time. While a developer'sefforts might be complex and time-consuming in an absolute sense, suchefforts would be, nevertheless, a routine undertaking for those of skillin this art having benefit of this disclosure. It must be understoodthat the inventions disclosed and taught herein are susceptible tonumerous and various modifications and alternative forms. Lastly, theuse of a singular term, such as, but not limited to, “a,” is notintended as limiting of the number of items. Also, the use of relationalterms, such as, but not limited to, “top,” “bottom,” “left,” “right,”“upper,” “lower,” “down,” “up,” “side,” and the like are used in thewritten description for clarity in specific reference to the Figures andare not intended to limit the scope of the invention or the appendedclaims.

Particular embodiments of the invention may be described below withreference to block diagrams and/or operational illustrations of methods.It will be understood that each block of the block diagrams and/oroperational illustrations, and combinations of blocks in the blockdiagrams and/or operational illustrations, can be implemented by analogand/or digital hardware, and/or computer program instructions. Suchcomputer program instructions may be provided to a processor of ageneral-purpose computer, special purpose computer, ASIC, and/or otherprogrammable data processing system. The executed instructions maycreate structures and functions for implementing the actions specifiedin the block diagrams and/or operational illustrations. In somealternate implementations, the functions/actions/structures noted in thefigures may occur out of the order noted in the block diagrams and/oroperational illustrations. For example, two operations shown asoccurring in succession, in fact, may be executed substantiallyconcurrently or the operations may be executed in the reverse order,depending upon the functionality/acts/structure involved.

In general terms, we have invented systems and processes for efficientlyand controllable sulfiding catalyst resident in a reactor vessel throughmeasurement, control, and continuous real time reporting of reactantsand operational parameters. Our systems and methods may comprise afront-end sulfur supply system and a back-end detection system. A sulfursupply system may be configured to provide a sulfur source, such as, butnot limited to, liquid dimethyl disulfide (DMDS) using a controlled andcontrollable pump, a fluid property measurement device, such as aCoriolis flow measurement instrument, and a data transmission component.A hydrogen sulfide detection system may comprise a real-time orquasi-real-time H₂S detection component and a data transmissioncomponent. A hydrogen gas detection component may comprise a real-timeor quasi-real-time H₂ detection device and a transmission component,which may be the same transmission component as the used by the hydrogensulfide detection system. A water detection component may comprise areal-time or quasi-real-time water detection device and a transmissioncomponent.

In a preferred, but non-limiting embodiment, a sulfur supply system, ahydrogen sulfide detection system, a hydrogen gas detection system and awater detection system transmit data wirelessly to one or more computersfor data display and/or system control, and/or the Internet fordistribution to others for display and/or system control. By collectingand processing data from the sulfur supply system, the hydrogen sulfidedetection system, the hydrogen gas detection system and/or the waterdetection system, the apparatuses and methods of our inventionsefficiently and effectively control and/or reduce the amount of sulfurconsumed in the sulfiding process; efficiently and effectively reducethe amount of unwanted or unneeded H₂S generated; and efficiently andeffectively reduce the amount of sulfur oxides that are introduced intothe atmosphere by flaring unwanted H₂S, and other sulfiding byproducts.

Turning now to the figures, FIG. 1 illustrates in general fashion ahydroprocessing system 100, comprising a process inlet through whichhydrocarbon feedstock 102 may enter the system 100. A pump or otherpressurizing device 104 may be used to introduce the feedstock 102 intothe system 100. A heat exchanger 106, such as a furnace, may be used asneeded to heat the feedstock 102 to the appropriate temperature rangefor the chemical processes involved in system 100. Heated feedstock 102may be introduced to a reactor vessel 108 for primary chemicalprocessing. Reactor vessel 108 typically contains a metal catalyst or aplurality of catalysts designed to increase the efficiency of thechemical reaction therein. Reactor products 110 may be fed to aseparator 112 where the reactor products 110 are separated into, forexample, their liquid and gas phases. The gas phase may be passedthrough another heat exchanger 114 to extract heat and thereby cool thegas so that it may be compressed 116 and returned to the reactor vessel108. A hydrogen gas makeup line 118 may be used to add hydrogen (H₂) gasto the process as needed. Liquid components of the reactor products canbe recirculated through line 120 to the input to reactor vessel 108. Theultimate or final product 122 of the system 100 may be extracted fromthe system 100 as shown. Waste or undesired products also can beextracted. Also illustrated in FIG. 1 is a low pressure flare line 124for combusting reaction products, waste products and other materials, asneeded and allowed.

It will be appreciated that FIG. 1 illustrates at a very high level thebasic components of a catalyst-based hydroprocessing system 100. FIG. 1is not intended to be a complete or actual hydroprocessing system. Itwill also be appreciated that catalyst-based hydrocarbon processingsystems such as illustrated in FIG. 1 typically require that the metalcatalyst periodically be re-charged or regenerated to maintain peakreaction efficiency.

FIG. 2 illustrates a refinery process 100 during a shutdown forsulfiding or re-sulfiding of the metal catalyst in reactor 108.Illustrated in FIG. 2 is a sulfiding module 200 comprising a sulfurproduct 202 inlet and a sulfur product outlet 204. As illustrated inFIG. 2, for liquid phase in-situ sulfiding the output 204 of sulfidingmodule 200 may be injected into process 100 at a location 204 a upstreamof pressurizing device 104, or at a location 204 b downstream ofpressurizing device 104 or at a location 204 c downstream of heatexchanger 106. It will also be appreciated that for gas phase in-situsulfiding output 204 may be injected into the gas recycle line 126.

It is contemplated, although not required, that sulfiding module 200 bea mobile unit, such as a trailer or sled, that can be transported to arefinery or to a location within a refinery adjacent a reactor vessel108 in need of catalyst sulfiding. As discussed previously, the sulfursource 202 may be any of a number of conventional sulfur-bearingproducts such as, but not limited to, liquid DMDS, and such sulfurproduct 202 may be drawn from containers, such as tanker trucks (notshown) and the like.

Turning now to FIG. 3, which illustrates one of many possibleembodiments of a liquid phase in-situ sulfiding module 200 implementedon a mobile platform. The sulfiding module 200 may comprise a sulfurinlet 202 and a one-way flow device or check valve 306 configured toprevent sulfur product 202 from backing out of the sulfiding module 200.Downstream of the check valve 306 is a pump 308 configured to pressurizethe liquid sulfur product 202 and inject it into the refinery process100, such as illustrated in FIG. 2. Although liquid DMDS is used as thesulfur source 202 in this particular embodiment, it will be appreciatedthat gaseous forms of sulfur may be used, and in such cases pump 308would be replaced with a compressor or other device capable ofpressurizing a gas for injection into the process 100. It is presentlypreferred that the pump 308 be a semi-positive displacement type pump,such as a radial vane pump, and that the pump 308 be controllable, suchas by a variable frequency drive and an A/C motor (not shown). Forexample, a low-pressure sulfiding module 200 may comprise a pump 308configured to delivery between about 40 gallons/minute and about 60gallons/minute of sulfur product 202 at about 200 psig to about 250psig. Alternately, a high-pressure sulfiding module 200 may comprise apump 308, such as a high pressure positive displacement triplex pump,configured to delivery between about 14 gallons/minute and about 20gallons/minute of sulfur product 202 at a pressure up to about 3,000psig. Those of skill having benefit of this disclosure will appreciatethat a single sulfiding module 200 may comprise dual pressure systems.It will be appreciated that a sulfiding module 200 may be designed withother types of pumps or fluid pressurizing devices, including positivedisplacement pumps, centrifugal pumps, compressors and other types offluid pressurizing devices.

Also illustrated in FIG. 3 is a pump bypass conduit 310 for thosesituations where the suction side of the process pump 104 may be used todraw sulfur product 202 into the system 100. Controllable valves 312 and314 are shown and may be configured to allow the sulfur product 202 topass through pump 308 or to bypass pump 308, as required for thespecific process 100 at issue. Also shown in FIG. 3 is an additionalone-way flow device or check valve 316 configured and located to preventsulfur product 202 from backflowing into pump 308.

Once the sulfur-bearing liquid product 202 has passed through pump 308or bypassed pump 308, the sulfur product 202 passes through a fluidmeasurement device 318 preferably capable of measuring a variety ofproperties of liquids and/or gases. At a minimum, it is preferred thatthe measurement device 318 be capable of measuring the volumetric flowrate of sulfur product 202. It is preferred, however, that themeasurement device 318 be capable of and configured to measure andreport not only volumetric flow rate but also mass flow rate, density,temperature, and other fluid properties. It is preferred that themeasurement device 318 also be capable of indicating a loss of sulfurproduct or “dry pipe” condition to avoid pump 308 cavitation. Forexample and without limitation, it is presently preferred that themeasurement device 318 be an Endress+Hauser ProMass 83E Coriolis massflow measuring instrument. After passing through measurement device 318,the sulfur product 202 may pass through a final controllable valve 220and exits the sulfiding module 200 through outlet 204.

FIG. 3 also illustrates that sulfiding module 200 may, and preferablydoes, comprise a controller 322 configured to receive inputs from and toprovide outputs, such as control signals, to, at least, one or more ofcontrollable valves 312, 314 and 320, pump 308 and measurement device318. Controller 322 may comprise a microprocessor, programmable gatearray, PID controller or other programmable logic device 324, a humaninput device 326, such as a keyboard or touchscreen, a visual displaydevice 328, such as a liquid crystal display or other device capable ofpresenting visual information, memory, a power supply 330 for poweringthe controller 322 components and/or a communications component 332.Communications component 332 may comprise a wired or wirelesscommunications interface. These various components of controller 322 areall configured and arranged in known fashion to provide data gathering,reporting and/or control of at least the various components on thesulfiding sled 200. It is preferred that the communications module 332be a wireless interface or a wireless cellular interface, allowingmonitoring and/or control of the sulfiding module 200 from one or morelocations remote to the module 200. For example, and without limitation,the communications module 332 may allow the process 100 owner to monitorin substantially real time the pre-sulfiding process as reported bycontroller 332. Further, wireless and wired connection allows remotecontrol of the sulfiding system from a computer or smartphone, such as,but not limited to, in the event of plant shut down or evacuation.

FIG. 4 illustrates the sulfiding system 200 shown in FIG. 2 with theaddition of a combined hydrogen sulfide/hydrogen gas module 400. As iswell known, during the sulfiding process, H₂S and H₂O are byproducts ofthe decomposition of the sulfur product 202, e.g., DMDS. It is known tomeasure the amounts of hydrogen sulfide generated during the sulfidingprocess to understand how the sulfiding process is progressing.Typically, H₂S levels during sulfiding are measured using Draeger-Tubes®with self-contained breathing apparatuses and hand-held pumps designedto draw a fixed amount of gas into the tube on each pump stroke. It isalso known that the sulfiding reaction requires the presence of hydrogen(H₂) gas and that decomposition of sulfur product 202 creates gasses,such as, but not limited to, methane that dilute the concentration ofhydrogen gas in the reactor vessel 108.

As illustrated in FIG. 4, module 400 has an input 402, which preferablycomprises a conduit plumbed between the process 100 and the module 400.The module 400 is configured to periodically, including substantiallycontinuously, sample a portion of the sulfiding gas returning to reactorvessel 108 downstream of cooling heat exchanger 114, and preferablyupstream of the compressor 116. It will be appreciated that depending onthe configuration of the module 400 and the system 100, the gas samplemay be obtained immediately downstream of separator 112, or downstreamof compressor 116. As will be described in more detail below, thegaseous sample 402 is provided to module 400 for analysis, such as, forexample, quantitative measurement, and reporting, such as to sulfidingmodule 200, and particularly controller 322, or to an external site suchas a remote computer or the Internet. Once the gas sample has beentested, it may be sent to flare line 124 via outlet 404 or sent to othersystems capable of disposing of or scrubbing the gas, such as venting toatmosphere, if appropriate.

As shown in FIG. 5, module 400 may comprise a hydrogen sulfide (H₂S)detection or analyzer system 502, such as, but not limited to, a leadacetate detection system, such as those available from Galvanic AppliedSciences, Inc. As is known, exposure of lead acetate tape to hydrogensulfide results in a darkening of the white tape because of theformation thereon of lead sulfide. Module 400 may use a lead acetatedetector system, or alternately, an electrochemical detector, such asthe Model 5100 H₂S Detector by Sierra Monitor, or other H₂S detectionsystem. Preferably, the H₂S detection system used is capable ofreal-time or quasi-real-time detection and electronic reporting. If alead acetate detection system 502 is used for module 400, it ispreferred that an optical scanner or other device for convertinginformation on the lead acetate tape into an electrical output, such asdigital information, be used. Regardless of the detection system used,it may be desirable or necessary to provide a plurality of detectionranges, such as 0-500 ppm, 0-20,000 ppm and 0-30,000 ppm.

Module 400 may also comprise, and preferably does comprise, a hydrogen(H₂) gas detector 504, such as, but limited to, the HY-OPTIMA 2740Explosion Proof In-Line Process Hydrogen Monitor available from H₂ScanCorporation. The type of hydrogen gas detector that can be used is notintended to be limited and includes detectors that are based on surfaceplasmon resonance sensors, electrochemistry sensors, MEMS sensors, thinfilm sensors, thick film sensors, chemochronic sensors, diode basedsensors or metallic sensors. If a H₂ detector 504 is used, it ispreferred that it also be capable of real-time or quasi-real-timedetection and electronic reporting.

As illustrated in FIG. 5, a quantity of recycle gas 402 enters module400 and, if present, preferably passes through hydrogen detector 504,which determines the concentration of hydrogen gas in the sample 402.The sample 402 then may pass through a coalescing filter 506 to removewater and hydrocarbon liquids that may be entrained in sample 402. Itwill be appreciated that depending on the type of hydrogen detector 504used, the coalescing filter may be placed upstream of the hydrogendetector 504. Liquids coalesced by the filter 506 may drop out to moduleoutlet 404 for communication with flare line 124, for example. Afterpassing through the filter 506, the gas sample 402 may preferably passthrough a flow meter 508, such as, but not limited to, a variable areaflow meter, including a rotameter. It is not typically necessary for theflow meter 508 to be capable of electronic reporting, but suchfunctionality is not excluded. The flow meter 508 will typically haveassociated therewith an adjustable orifice, such as a needle valve, tofinely adjust the flow rate of the gas sample 402 ultimately deliveredto the H₂S detector 502. Shown disposed between the filter 506 and theflow meter 508 is controllable valve 510, which preferably also haspressure relief capabilities. The valve 510 can be closed in which statethe gas sample 402 will pass through outlet 404. Also, if the gaspressure exiting filter 506 is too high for H₂S detector 502 (or H₂detector, if so plumbed), the relief valve will open thereby venting thegas sample to the outlet 404.

Once gas sample 402 passes through flow meter 508, it passes into adiffusion chamber 511. Diffusion chamber 511 comprises a permeablemembrane 512, such as permeable tubing. Nitrogen gas 514, typicallysupplied by the refinery, enters the module 400 as shown and may passthrough a flow control valve or metering valve 516 and/or a controllablevalve 518 before it reaches a flow meter 520, such as, but not limitedto a variable area flow meter, including a rotameter. Similar to flowmeter 508, it is not typically necessary for the flow meter 520 to becapable of electronic reporting, but such functionality is not excluded.The flow meter 520 will typically have associated therewith anadjustable orifice, such as a needle valve, to finely adjust the flowrate of nitrogen gas 514 ultimately delivered to the diffusion chamber511. For the lead acetate based detector 502 in this example, the gassample 402 is diluted at a ratio of about 1 part gas sample to about1000 parts nitrogen gas.

Inside the diffusion chamber 511, H₂S gas diffuses into the nitrogen gasstream separated by the permeable membrane 512 and the combined H₂S andN₂ gas stream is fed to the lead acetate H₂S detector 502, asillustrated. The H₂S detector 502 determines the concentration of H₂S inthe sample and generates an electronic signal representative of the H₂Sconcentration. In this example, because H₂S detector 502 is a leadacetate detector, the gas sample that exits detector 502 is free, orsubstantially free, of H₂S and the gas sample may be vented toatmosphere 522 after, preferably, passing through a carbon filter 524.It will be appreciated that if other types of H₂S detectors are used,such as, but not limited to, electrochemical detectors, the arrangementand plumbing within module 400 may change according to the operatingparameters and requirements of the detector. And, the gas sample exitingthe detector may need to be plumbed to the flare line 124 instead ofvented to atmosphere.

Module 400 may also comprise, and preferably does comprise acommunications module 526 that can communicate wirelessly or over wireto sulfiding module 200 or to a remote site, including a remotecontroller, computer or the Internet. In a preferred embodiment, module200, and, for example, controller 322, is configured to receive awireless data transmission from module 400 and, report, for example, thehydrogen sulfide concentration data and hydrogen gas concentration datathrough communications module 332. Alternately, or additionally, module200 and specifically controller 322, can use the data obtained from themodule 400 to control the sulfiding process. For example and withoutlimitation, as the hydrogen sulfide concentration increases in the gassample from the sulfiding process, controller 322 can slow down sulfurpump 308 or otherwise adjust the amount of sulfur product been suppliedto the sulfiding process. Similarly, as the H₂ gas concentrationdecreases in the gas sample 402, the refinery operator can supplyadditional H₂ gas through H₂ makeup line 118.

Module 400 may also comprise a controller 528, such as a microprocessor,programmable gate array, PID controller or other programmable logicdevice 324. The controller also may be operatively coupled to a humaninput device, such as a keyboard or touchscreen, a visual displaydevice, such as a liquid crystal display or other device capable ofpresenting visual information, memory, a power supply for powering thecontroller 322 components and the communications component 526. It willbe appreciated that the controller 528 and communications component 526may interact to allow control of the components associated with module400.

Although this description of an embodiment of module 400 comprises acombined H₂S and H₂ detection capability, it will be appreciated thatmodule 400 can have H₂S only detection capability, H₂ only detectioncapability or the combined ability as described. Also, separate H₂S andH₂ modules can be used together as described above.

Having now described embodiments of our sulfur supply module 200 and ourdetection module 400, we turn now to a discussion of one of manypossible embodiments of an in-situ sulfiding method using ourinventions. In practice, a sulfur supply module 200 and a combinedhydrogen sulfide and hydrogen gas detection module 400 may be deliveredto a refinery location and positioned adjacent a hydroprocessing unit100 having catalyst to be sulfided. The outlet 204 of the sulfur supplymodule 200 may be plumbed into a preferably existing injection port (notshown) in the hydroprocessing unit 100. As described with respect toFIG. 2, such injection port may be located at locations 204 a, 204 b,204C or other suitable sulfur injection site or sites. A supply ofsulfur product, such as, but not limited to liquid DMDS, will beprovided, such as in the form of a tanker truck or trucks. Aconventional suction hose resistant to the sulfur product can be plumbedbetween the tanker truck outlet and the inlet 202 to sulfiding module200. Similarly, the detection module 400 may be placed adjacent aportion of the hydroprocessing unit 100 where access to the sulfidinggas return 126 is provided. A flexible conduit is preferably attached toa valved extraction port already existing in the hydroprocessing unit100 and plumbed to the inlet port 402 on the module 400.

It is preferred, but not required, that that the connections andcomponents of sulfiding module 200 be leak tested before the sulfurproduct is injected, such as by using diesel or other inexpensive,liquid hydrocarbon to test/purge all lines and connections. The dieselmay be injected by module 200 into the hydroprocessing system 100 afterset up of the sulfiding module 200 and prior to commencement of sulfurproduct injection into process 100. This leak testing with, for example,diesel reduces the risk of sulfur product leaks during sulfiding.Similarly, after sulfiding is completed, a post-sulfiding purge of thesulfiding module 200 and reactor vessel 108 may be performed in similarfashion.

Power in the form of AC energy supplied by the refinery or DC batterypower supplied on the sulfiding module 200 and detection module 400, orpower supplied by a portable generator may be supplied to both modules200 and 400. Both modules may be powered up and the equipmentinitialized and checked. The communication link, whether wired orwireless, may be established. In a preferred embodiment, a laptopcomputer may be used to establish wireless communication among thesulfiding module 200, the detection module 400 and the laptop (notshown). The wireless link among these modules and the laptop computerallows the laptop computer and operator to see the operating conditionof all components.

FIG. 6 illustrates a typical sulfiding temperature profile for sulfidinga metal catalyst with liquid DMDS. Once the hydroprocessing unit 100 isready for the sulfiding process the catalyst in reactor vessel 108 maybe dried in conventional fashion, such as by purging the reactor vessel108 with hydrogen gas (typically supplied by the refinery), or other drygas, or with liquid feedstock. As an example only, the reactor vessel108 may be run up to a temperature of about 300° F. and pressure ofabout 200 psig to about 500 psig on hydrogen gas for a period tosatisfactorily dry the metal catalyst therein. Thereafter, during thewetting step, the reactor temperature is reduced to between about 150°F. to about 250° F. and hydrocarbon feedstock is introduced to wet thecatalyst.

After wetting, the reactor temperature is increased to the sulfursource's (e.g., DMDS) H₂S decomposition temperature range, such as about350° F. to 450° F. At this point in the temperature profile 602, and asshown in FIG. 6, the sulfiding module 400 may be energized and thecontroller 322 starts pump 104 to begin delivery of the sulfidingproduct, such as DMDS, into the hydroprocessing unit 100 at a first flowrate. During this first sulfiding phase or plateau, the temperatureremains relatively constant at about 350° F. to 450° F. for an extendedperiod, and the flow rate of sulfur product typically will gradually orstep-wise increased. As is known, H₂S removal from the recycle gasstream is discontinued, when possible, until sulfiding is completed.During this first phase of sulfiding, H₂S concentration in the recyclegas will remain relatively low, such as about 30 ppm to about 160 ppm oreven up to about 200 ppm. As is also known, hydrogen gas may need to beintroduced into the hydroprocessing unit 100 to ensure a reasonablyconstant and appropriate hydrogen gas concentration in the reactorvessel 108.

This first sulfiding phase or plateau effectively ends at a point 604,which is often referred to as H₂S breakthrough. Theoretically, H₂Sbreakthrough occurs when the reactants reach thermodynamic equilibriumat given process mass flux. In reality, H₂S breakthrough is recognizedwhen H₂S concentration in the recycle gas 402 rapidly increases. Thepresent invention will detect and report this increase in H₂S inessentially real time by detection module 200. H₂S breakthroughtypically is not a universally accepted H₂S concentration value, andusually refinery operators have their own standard for when breakthroughis recognized. For example, and without limitation, breakthrough may beconsidered to occur when H₂S concentrations reach about 3,000 ppm orhigher, even up to about 5,000 ppm. In theory, approximately one-half ofthe stoichiometric amount of sulfur should have been injected beforebreakthrough is reached. In practice, the percentage can range fromabout 50% to about 65% of the stoichiometric amount. The fluidmeasurement device 318 in module 200 may be configured to substantiallycontinuously report the total mass or volume flow of sulfiding agentthat has been injected at any point in time and, therefore, thesulfiding module 400 can report when the stoichiometric breakthroughpoint (by mass) is approaching or has been reached.

Regardless of how or when breakthrough is determined, as shown in FIG.6, once H₂S breakthrough is determined, the reactor temperature israised to about 600° F. to about 650° F. by use of heat exchanger 106 toincrease the sulfiding of the catalyst. The rate of temperature increasetypically will depend on the metallurgical constraints of the process100, and is usually controlled by the process operator. At this point606 in the temperature profile, the second sulfiding regime or plateaubegins and the temperature remains relatively constant at about 600° F.to about 650° F. for a period until sulfiding is complete; e.g., untilthe pre-determined amount of sulfur product has been injected.

As will be discussed in more detail below, during this sulfiding processthe flow rate of sulfur product (e.g., DMDS) supplied by module 200 canbe controlled by ator accessing the controller 322, through thecommunications link, such as via a laptop or Internet computer, andissuing commands to controller 322 and, therefore, pump 104.Alternately, controller 322 can automatically control the flow rate ofsulfur product according to logic steps or programming residing in oneor more memory modules accessible by controller 322.

At the back end of the hydroprocessing unit 100, the detection module400 continuously or substantially continuously monitors the hydrogensulfide concentration and hydrogen gas concentration of the sulfidinggas (recycle gas) that is returned to the reactor 108. The data suppliedby the module 400 may be used by the operator and/or controller 322 toincrease the supply of sulfur product 202 to the sulfiding process or todecrease the amount of sulfur product to the sulfiding process. Forexample, if the total H₂S content in the gas decreases below apredetermined value (such as, for example, 1,000 ppm) controller 322 cancause, either through operator input or by pre-programmed logic, thesulfiding module 200 to increase the supply of sulfur product to thecatalyst residing in reactor 108. Alternately, as the amount of H₂S inthe recycle gas stream increases to, for example, 10,000 ppm or above,controller 322 can decrease the amount of sulfur product supplied to thesystem 100. For example, our sulfiding methods and systems can controlthe injection of sulfur product (i.e., control pump 104) by monitoringthe H₂S concentration in the recycle gas. During sulfiding, the modules200 and 400 can interact and cooperate, alone or with external input, tomaintain H₂S concentrations between about 3,000 ppm and 23,000 ppm, asshown in FIG. 7, and most preferably between about 3,000 ppm and 10,000ppm. By preferentially and proactively controlling the amount of H₂S inthe recycle gas, the amount of waste hydrogen sulfide that has to beflared or otherwise disposed of can be minimized. It will be appreciatedthat minimizing the flaring of hydrogen sulfide gas reduces, if noteliminates, a refinery's potential sulfur oxide emissions caused duringsulfiding operations.

Referring again to FIG. 7, the graph shows hydrogen sulfideconcentration in the sample gas from the recycle line versus processtime, and sulfur product flow rate versus process time. FIG. 7illustrates that on beginning of the sulfiding process at point 602, theflow rate of sulfur product is increased, preferably in stepwisefashion, to create a buildup of hydrogen sulfide gas during this firstsulfiding stage. Once H₂S breakthrough is recognized at, for example,point 604 because of an increase in H₂S gas, the flow rate of sulfurproduct 202 may be adjusted, such as decreased or increased, to maintainan optimum concentration of H₂S and avoid an overabundance of waste H₂S.The flow rate of the sulfur product may be adjusted by varying the speedof pump 108 or by adjusting controllable valve 320, or a combination ofboth actions. FIG. 7 also illustrates what is commonly referred to asecond H₂S breakthrough 702 when using liquid DMDS as the sulfur source.When this second breakthrough is recognized, it typically marks completesulfiding of the catalyst and sulfur product injection can besubstantially decreased, including stopped. For example, and in contrastto what is illustrated in FIG. 7, if the inventions described herein areconfigured to limit H₂S concentration to 10,000 ppm, when the secondbreakthrough is recognized, the inventions described would reduce thepump 108 speed dramatically to prevent the H₂S concentration in the gasstream from exceeding 10,000 ppm. This type of control strategy based onH₂S concentration will reduce the amount of sulfur product consumed anddecrease the amount of waste H₂S gas that must be sent to the flare line124 or amine scrubber.

FIG. 8 illustrates one of many possible embodiments of a remotelydisplayed sulfiding system interface 800 for use with the presentinventions. This interface 800 screen is the product of a properlyconfigured and programmed sulfiding module 200 and detection module 400,and has a simplified piping diagram of a sulfiding module 802 similarbut not identical to sulfiding module 200 discussed in FIGS. 2 and 3. Adetection module, such as module 400 in FIG. 4, is represented by H₂Sdisplay 804 and H₂ display 840. Display 804 can indicate the sensitivityor range that the hydrogen sulfide detection module is currentlyoperating in and the interface can be used to change between the ranges.The display 804 also has indicators that can show when H₂S breakthroughhas been reached. As discussed above, because this point in the processis not precisely defined, the system allows the breakthrough H₂Sconcentration to be programmed into the interface for each sulfidingprocess. Display 800 also has a high H₂S level indicator that may beprogrammed to show when the sulfiding process is complete, such as whenboth the breakthrough and high level indicators are energized. Theinterface can be configured such that after the first breakthrough pointis recognized, the rate of change H₂S concentration is determined and anincreasing rate of change may be used to indicate that the secondbreakthrough has been reached.

The sulfiding module 802 illustrated in FIG. 8 shows two sulfur productinlets 806 and 808, each with controllable valves 810 and 812. Theinterface preferably has the ability to indicate the state, such asopened or closed, of the inlet valves, 810 and 812, and register thosestates on the display. The inlets are shown to communicate with a pump814 and a pump bypass loop 816. The pump 814 is preferably driven by anAC motor having a variable frequency drive (not shown). The status ofthe pump 814 is shown by readout 816, which can display revolutions perminute, frequency or pump flow volume. The flow measurement device 318described in FIG. 3 is represented in interface 800 by readout 818showing sulfur product pressure, readout 820 showing sulfur producttemperature and readout 822 showing sulfur product flow rate. Additionalreadouts may be added depending on the functionality of the fluidmeasurement device actually used. For example, a sulfur product densityreadout and/or sulfur concentration readout may be utilized. Interface800 also shows two sulfiding module outlets 834 and 836 and associatecontrollable valves 838 and 840. Although not shown, interface may alsoprovide a “dry pipe” condition indicating that flow of sulfur producthas been interrupted.

Interface 800 shows a pump status window that can report whether thepump is running or not and allow for emergency pump stop. A sulfurproduct volumetric flow rate setpoint window 826 is shown and the flowrate set point can be set by accessing the controller 322 on module 200.Also shown on interface 800 is a total volumetric flow rate windowshowing the total sulfur product injected into the hydroprocessing unit100 at any particular time. Although not shown, interface 800 maypresent a H₂S breakthrough set point window in which the totalvolumetric flow is shown that correlates to 50% to about 65% of thestoichiometric sulfur needed to completely sulfide the catalyst, asdiscussed above.

Interface 800 also shows that more than one sulfiding module may be usedto inject sulfur product into the hydroprocessing unit 100. Remote flowreadout and remote flow totalizer window 832 provide information onsecond sulfiding module injecting sulfur product a second location inthe unit.

FIG. 8 also shows that the interface may comprise a message window 842that permits written or graphic communication among users of theinterface. For example, the sulfiding contractor may use the messagingcapability to inform the process 100 operators of a need for hydrogenmakeup.

FIG. 8 also shows that the interface may comprise water flow rate andtotal water extracted. It is known that water is a byproduct of thesulfiding process and the process operators will routinely monitor andextract water from process 100 such as through outlet 122 shown in FIG.4. The present inventions may also comprise a non-contact waterdetection device 426 (see FIG. 4) that can be coupled to outlet 122 todetect and report to interface 800 (and/or controller 322) the flow rateof water and the total of water extracted from the system duringsulfiding. It will be appreciated that the amount of water generated bythe sulfiding reaction is a direct measure of how the sulfiding reactionis progressing. As illustrated in FIG. 4, it is preferred that the waterdetection device 426 have the ability to wirelessly communicate with theinterface 800 and/or the controller 322.

Once catalyst sulfiding has been completed, the present inventions cangenerate a sulfiding report, such as illustrated in FIG. 7, and whichcan further include parameters such as total mass and volume of sulfurinjected, total water removed, and other data or parameters recorded,monitored or indicated during the sulfiding process.

In a preferred embodiment, the sulfiding module and the detection modulecan be monitored and controlled via a wireless data and communicationlink among the modules and a computer, such as a conventional laptop ordesktop computer. The interface is preferably configured to allowmonitoring and control of all aspects of the sulfiding module and thedetection module. Alternately, the monitoring and control may beaccomplished by a suitable configured website using conventionalprogramming techniques to accomplish the functionality described herein.Still further, monitoring and control can be accomplished through asmart phone application.

Other and further embodiments utilizing one or more aspects of theinventions described above can be devised without departing from thespirit of Applicant's invention. For example, although the inventionswere described primarily with liquid sulfur sources, the inventions canbe used with gaseous sulfur products. Also, the interface described canallow for both manual, operator control of the equipment and automatic,preprogrammed operation. Further, the various methods and embodiments ofthe methods of manufacture and assembly of the system, as well aslocation specifications, can be included in combination with each otherto produce variations of the disclosed methods and embodiments.Discussion of singular elements can include plural elements andvice-versa.

The order of steps can occur in a variety of sequences unless otherwisespecifically limited. The various steps described herein can be combinedwith other steps, interlineated with the stated steps, and/or split intomultiple steps. Similarly, elements have been described functionally andcan be embodied as separate components or can be combined intocomponents having multiple functions.

The inventions have been described in the context of preferred and otherembodiments and not every embodiment of the invention has beendescribed. Obvious modifications and alterations to the describedembodiments are available to those of ordinary skill in the art. Thedisclosed and undisclosed embodiments are not intended to limit orrestrict the scope or applicability of the invention conceived of by theApplicants, but rather, in conformity with the patent laws, Applicantsintend to fully protect all such modifications and improvements thatcome within the scope or range of equivalent of the following claims.

What is claimed is:
 1. A system for sulfiding a metal catalyst,comprising: a mobile sulfur supply module comprising a sulfur productinlet and outlet, a sulfur product measurement device, a sulfur productpressurization device having a variably controllable output, acontroller in electrical communication with at least the measurementdevice and pressurization device, and a first communication deviceconfigured to transmit information between the module and an externalsite; a mobile detection module comprising an inlet and outlet, ahydrogen sulfide concentration detection device located between theinlet and outlet, a hydrogen gas concentration detection device locatedbetween the inlet and the outlet, and a second communication deviceconfigured to transmit information between the mobile detection moduleand the sulfur supply module or between the mobile detection module andthe external site.
 2. The system of claim 1, wherein the external siteis a laptop computer.
 3. The system of claim 1, wherein the externalsite is a website on the Internet.
 4. The system of claim 1, wherein thepressurization device comprises a pump.
 5. The system of claim 4,wherein the pump comprises an AC motor and a variable frequency drive.6. The system of claim 1, wherein the pressurization device comprises acompressor.
 7. The system of claim 6, wherein the compressor comprisesan AC motor and a variable frequency drive.
 8. The system of claim 1,wherein the sulfur product measurement device comprises amulti-parameter fluid measurement device.
 9. The system of claim 8,wherein the fluid measurement device is configured to determinevolumetric flow rate, mass flow rate, fluid density, fluid pressure andfluid temperature.
 10. The system of claim 9, wherein the fluidmeasurement device comprises a Coriolis meter.
 11. The system of claim1, wherein both communication devices are configured to transmitinformation wirelessly.
 12. The system of claim 11, wherein thedetection module is configured to transmit information to the sulfursupply module for use in controlling the output of the pressurizationdevice.
 13. The system of claim 12, wherein the detection module isconfigured to transmit hydrogen sulfide concentration information to thesulfur supply module for use in controlling the output of thepressurization device.
 14. The system of claim 11, wherein the sulfursupply module and the detection module are configured to transmitinformation to an Internet website.
 15. The system of claim 14, whereinthe sulfur supply module and the detection module are configured totransmit hydrogen sulfide concentration information to the Internetwebsite and the website is configured to transmit information to thesulfur supply module for use in controlling the output of thepressurization device.
 16. The system of claim 11, wherein the sulfursupply module and the detection module are configured to transmitinformation to an Internet website for use in controlling the output ofthe pressurization device.
 17. The system of claim 1, further comprisinga water detection device configured to determine an amount of watergenerated while sulfiding the catalyst.
 18. The system of claim 17, thewater detection device comprises a removable, non-contact sensor havinga third communication device configured to transmit information betweenthe water detection device and an external site or between the waterdetection device and the sulfur supply module.
 19. A system for liquidphase in-situ sulfiding of a metal catalyst, comprising: a sulfur supplymodule comprising a fluid measurement device comprising a Coriolismeter, a fluid pump having a variably controllable output comprising anA/C motor and a variable frequency drive, a controller in electricalcommunication with at least the measurement device and variablefrequency drive, and a first wireless communication device configured totransmit information to and from the module; a mobile detection modulecomprising a hydrogen sulfide concentration detection device locatedbetween a detection module inlet an outlet, a hydrogen gas concentrationdetection device located between the inlet and the outlet, and a secondcommunication device configured to transmit information to and from thehydrogen sulfide detection device and to and from the hydrogen gasdetection device.
 20. The system of claim 19, further comprising anInternet website configured to receive information transmitted by thesulfur supply module, the hydrogen sulfide detection module and thehydrogen gas detection module, and to display the information receivedin substantially real time.